Kessinger told the newspaper that since his arrest, she has had no doubt that he committed the crimes.

Chris Watts is set to be sentenced Monday after he pleaded guilty to all charges against him: five counts of murder in the first degree; three counts of tampering with a deceased human body; and one count of unlawful termination of pregnancy.

In exchange for the guilty plea, prosecutors will not pursue the death penalty, the Weld County District Attorney's office said. The victims' family agreed to those terms, the district attorney's office added.